Composition, magnetic body, substrate with magnetic body, and electronic component

Abstract

The first problem addressed by the present invention is to provide a composition which is excellent in reduced-pressure coating properties and which contains a low amount of residual solvent in a product obtained after heat treatment. The second problem addressed by the present invention is to provide a magnetic body obtained by curing the composition. The third problem addressed by the present invention is to provide an electronic component and a substrate with a magnetic body pertaining to the magnetic body.　The composition according to the present invention contains magnetic particles and a solvent. The solvent contains at least one type of specific solvent having a boiling point of 300°C or less and satisfying the relationship of formula (1).　Formula (1): (vapor pressure of the specific solvent at 25°C in units of Torr) × (molecular weight of the specific solvent) < 0.53

Description

Composition, magnetic material, substrate with magnetic material, electronic component

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

[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 (hereinafter also referred to as "magnetic compositions").

[0003] For example, Patent Document 1 discloses a magnetic composition containing magnetic particles, a heterocycle-containing compound whose Hansen solubility parameter polarity term and hydrogen bonding term satisfy predetermined numerical ranges, a compound selected from the group consisting of epoxy compounds and oxetane compounds, and a dispersant. The magnetic composition is prepared by further containing an organic solvent such as glycerol triacetate in addition to the above components.

[0004] International Publication No. 2023 / 189325

[0005] Recently, for example, when filling holes in a substrate with a magnetic composition, the filling process is sometimes performed under reduced pressure to improve filling accuracy. The present inventors, referring to Patent Document 1, prepared and studied a magnetic composition containing glycerol triacetate as a solvent. They found that when the composition was applied under reduced pressure, the viscosity of the composition changed during the process due to the evaporation of the solvent, resulting in unstable application properties. This finding revealed that there is room for further improvement in the composition's application properties under reduced pressure. After the composition is filled into the holes, it is typically subjected to a process such as heat treatment to remove the solvent and / or harden the curable components. However, from the perspective of magnetic property stability, it is also desirable for the product (magnetic material) obtained by the heat treatment to contain a small amount of solvent. While a method of using a diluent monomer instead of a solvent to achieve the desired application properties is also available, the use of a diluent monomer results in a relatively lower magnetic particle content in the product (magnetic material) obtained by the heat treatment compared to the use of a solvent, making it difficult to obtain good magnetic properties.

[0006] Therefore, an object of the present invention is to provide a composition that has excellent reduced-pressure coatability and has little residual solvent in the product obtained after heat treatment. Another object of the present invention is to provide a magnetic body obtained by curing the composition. 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 composition comprising magnetic particles and a solvent, wherein the solvent has a boiling point of 300°C or less and contains at least one specific solvent that satisfies the relationship of formula (1): Formula (1): Vapor pressure of the specific solvent, expressed in Torr at 25°C, × Molecular weight of the specific solvent < 0.53. [2] The composition according to [1], wherein the melting point of the specific solvent is −10°C or less. [3] The composition according to [1] or [2], wherein, when the composition contains one type of magnetic particles, the average particle size of the magnetic particles is 20 μm or more; and when the composition contains two or more types of magnetic particles with different compositions, the two or more types of magnetic particles include at least one magnetic particle having an average particle size of 20 μm or more. [4] The composition according to any one of [1] to [3], wherein the total content of the specific solvent is 3 mass% or more relative to the total mass of the composition. [5] A magnetic body obtained by curing the composition according to any one of [1] to [4]. [6] A substrate with a magnetic body, comprising: a substrate having a hole formed therein; and the magnetic body according to [5] arranged in the hole. [7] An electronic component, comprising the substrate with a magnetic body according to [6].

[0009] According to the present invention, a composition can be provided that has excellent reduced-pressure coatability and has little residual solvent in the product obtained after heat treatment. The present invention also provides a magnetic body obtained by curing the composition. The present invention also provides 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, the term "boiling point" refers to the standard boiling point unless otherwise specified. In this specification, 1 Torr can be converted to 1 mmHg.

[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] [Composition] The composition of the present invention is a composition containing magnetic particles and a solvent, wherein the solvent contains at least one specific solvent having a boiling point of 300°C or less and satisfying the relationship of formula (1): formula (1): vapor pressure of the specific solvent expressed in Torr at 25°C × molecular weight of the specific solvent < 0.53

[0018] The composition having the above-described configuration has excellent reduced-pressure applicability and a small amount of residual solvent in the product obtained after heat treatment. Although the mechanism of action is not clear in detail, it is believed that when the specific solvent satisfies the relationship of formula (1), the solvent is less likely to evaporate during reduced-pressure application, resulting in excellent application stability. The left side of formula (1) is a parameter related to the ease of solvent evaporation; the smaller this value, the less likely the solvent is to evaporate, resulting in excellent reduced-pressure applicability. Furthermore, it has been found that when the boiling point of the specific solvent is 300°C or less, the amount of residual solvent in the product obtained by heating the composition is small, resulting in excellent magnetic properties.

[0019] Hereinafter, "the effect of the present invention is better" may mean that the reduced pressure application property of the composition is better and / or that the amount of residual solvent in the product obtained by heating the composition is smaller.

[0020] Each component that may be contained in the composition will be described below.

[0021] [Magnetic Particles] The composition contains magnetic particles. The magnetic particles typically contain metal atoms. In this specification, the metal atoms also include metalloid atoms such as boron, silicon, germanium, arsenic, antimony, and tellurium. The metal atoms may be contained in the magnetic particles as an alloy, metal oxide, metal nitride, or metal carbide containing the metal element.

[0022] The metal atoms are not particularly limited, but preferably contain at least one metal atom selected from the group consisting of Fe, Ni, and Co. The content of at least one metal atom selected from the group consisting of Fe, Ni, and Co (when multiple types are contained, the total content) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on 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.

[0023] The magnetic particles may contain materials other than Fe, Ni, and Co, 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, Zn, Sr, Zr, Mn, Cr, Nb, Pb, Ca, B, C, N, and O. When the magnetic particles contain metal atoms other than Fe, Ni, and Co, it is preferable that the magnetic particles further contain one or more elements selected from the group consisting of Mn, Zn, Si, Cr, B, and Mo.

[0024] 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.

[0025] The magnetic particles are preferably alloy particles. The alloy particles preferably contain Fe, as this provides a more excellent effect of the present invention. Examples of metal atoms other than Fe in the alloy particles include Ni and Co. When the alloy particles contain Fe, the Fe content is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, relative to the content of metal atoms in the alloy 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. The alloy particles may also be amorphous.

[0026] The volume-average particle size of the alloy particles is not particularly limited, and is often 1 to 60 μm. In terms of the effects of the present invention being more excellent, it is preferably 1 to 30 μm, and more preferably 1 to 20 μm. The volume-average particle size of the alloy particles is the so-called median size (D50), and can be determined based on a particle size distribution curve that represents the volume-based frequency distribution of the alloy particles obtained using a laser diffraction / scattering particle size distribution analyzer (for example, the "LA960N" product manufactured by Horiba, Ltd.).

[0027] Examples of alloy particles include Fe—Co-based alloy particles (preferably Permendur), Fe—Ni-based alloy particles (e.g., Permalloy), Fe—Zr-based alloy particles, Fe—Mn-based alloy particles, Fe—Si-based alloy particles, Fe—Al-based alloy particles, Ni—Mo-based alloy particles (preferably Supermalloy), Fe—Ni—Co-based alloy particles, Fe—Si—Cr-based alloy particles, Fe—Si—B-based alloy particles, Fe—Si—Al-based alloy particles (preferably Sendust), Fe—Si—B—C-based alloy particles, Fe—Si—B—Cr-based alloy particles, Fe—Si—B—Cr—C-based alloy particles, Fe—Co—Si—B-based alloy particles, Fe—Si—B—Nb-based alloy particles, Fe nanocrystalline alloy particles, Fe-based amorphous alloy particles, and Co-based amorphous alloy particles.

[0028] Ferrite particles are also preferred as magnetic 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 Ni, Mn, and Co, and more preferably contain at least one metal atom selected from the group consisting of Mn and Ni. In addition, the ferrite particles may contain materials other than Ni, Mn, Fe, and Co, 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, Zn, Sr, Zr, Cr, Nb, Pb, Ca, B, C, N, and O.

[0029] The volume-average particle diameter of the ferrite particles is not particularly limited, and is often 1 to 60 μm. In terms of better effects of the present invention, it is preferably 5 to 55 μm, more preferably 10 to 50 μm, and even more preferably 20 to 50 μm. The volume-average particle diameter 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 with a laser diffraction / scattering particle size distribution analyzer (for example, the "LA960N" product manufactured by Horiba, Ltd.).

[0030] Examples of ferrite particles include Ni ferrite, Mn ferrite, and spinel ferrite (preferably Ni—Zn ferrite, Mn—Zn ferrite, Ni—Zn—Co ferrite, or Fe—Mn ferrite).

[0031] Among the magnetic particles, soft magnetic particles are preferred because they have lower loss. Examples of soft magnetic particles include Fe-based amorphous alloy particles, Fe—Si—Cr-based alloy particles, Fe nanocrystalline alloy particles, Fe—Ni—Co-based alloy particles, Co-based amorphous alloy particles, Ni—Mo-based alloy particles, Ni ferrite particles, Mn ferrite particles, Ni—Zn-based ferrite particles, Mn—Zn-based ferrite particles, and Ni—Zn—Co-based ferrite particles.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The magnetic particles may be used singly or in combination of two or more types. When two or more types of magnetic particles are used in combination, it is preferable that the compositions of the two or more types of magnetic particles are different from each other. When two or more types of magnetic particles are used in combination, a combination of ferrite particles and alloy particles or a combination of alloy particles and alloy particles is preferable, and a combination of ferrite particles and alloy particles is more preferable. Furthermore, when ferrite particles and alloy particles are used in combination as the magnetic particles, the content ratio (mass ratio: ferrite particles / alloy particles) is preferably 30 / 70 to 70 / 30, more preferably 40 / 60 to 60 / 40. Furthermore, when alloy particles (first alloy particles) and alloy particles (second alloy particles) are used in combination as the magnetic particles, the content ratio (mass ratio: first alloy particles / second alloy particles) is preferably 30 / 70 to 70 / 30, more preferably 40 / 60 to 60 / 40. The magnetic particles may include spherically deformed magnetic particles. A spherically deformed particle refers to a particle in which a part of a spherical particle has been cut off by a flat surface. The spherically deformed magnetic particle in the state before the crown portion of the spherically deformed magnetic particle is cut off does not necessarily have to be a perfect sphere, and typically, a sphericity of 100 to 140 is preferred. Furthermore, the flat surface of the spherically deformed magnetic particle may have minute irregularities. In other words, the surface exposed by cutting off the flat surface of the spherically deformed magnetic particle may not be a perfect flat surface, but may have irregularities.

[0037] The content of magnetic particles in the composition (the total content when multiple types of magnetic particles are included) is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 92% by mass or more, based on the total solid content of the composition, with the upper limit being preferably 97% by mass or less, more preferably 95% by mass or less.

[0038] In order to obtain a more excellent effect of the present invention, the composition preferably contains magnetic particles having an average particle size (volume average particle size) of 20 μm or more. That is, when the composition contains one type of magnetic particles, the average particle size (volume average particle size) of the magnetic particles is preferably 20 μm or more, and when the composition contains two or more types of magnetic particles having different compositions, the two or more types of magnetic particles preferably contain at least one type of magnetic particle having an average particle size (volume average particle size) of 20 μm or more.

[0039] Furthermore, when the composition contains two or more types of magnetic particles with different compositions, it is also preferable that at least one of the two or more types of magnetic particles has an average particle diameter (volume average particle diameter) of 20 μm or more (hereinafter also referred to as "magnetic particles A"), and at least one of the two or more types of magnetic particles has an average particle diameter (volume average particle diameter) of less than 20 μm (hereinafter also referred to as "magnetic particles B"). The lower limit of the average particle diameter of magnetic particles A is more preferably 25 μm or more, and even more preferably 30 μm or more. The upper limit is more preferably 100 μm or less, and even more preferably 80 μm or less. The average particle diameter of magnetic particles A can be measured by the method described below. The upper limit of the average particle diameter of magnetic particles B is more preferably 10 μm or less, and even more preferably 8 μm or less. The lower limit is more preferably 1 μm or more, and even more preferably 2 μm or more. The average particle diameter of magnetic particles B can be measured by the method described below.

[0040] Furthermore, when the composition contains two or more types of magnetic particles with different compositions, the content of magnetic particles A is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, relative to the total mass of the magnetic particles. There is no particular upper limit, and the content is preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, relative to the mass of the magnetic particles.

[0041] Furthermore, when the composition contains two or more types of magnetic particles with different compositions, the content of magnetic particles B is preferably 20% by mass or more, and more preferably 30% by mass or more, relative to the total mass of the magnetic particles. There is no particular upper limit, and the content is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less, relative to the mass of the magnetic particles.

[0042] The presence or absence of magnetic particles with an average particle size of 20 μm or more can be determined by the following procedure. First, magnetic particles are observed using a scanning electron microscope (SEM; for example, the "S-4800H" manufactured by Hitachi High-Technologies Corporation can be used), and 1,000 magnetic particles with the same composition are randomly selected and photographed in an arbitrary observation field. During the observation, elemental composition is analyzed using energy dispersive X-ray spectroscopy (EDS), making it possible to extract 1,000 magnetic particles with the same composition. The "S-4800H" manufactured by Hitachi High-Technologies Corporation can also analyze elemental composition using EDS. The elemental composition analysis can also identify the composition of the magnetic particles (e.g., the composition of ferrite particles and alloy particles, as well as the metal content in the magnetic particles).

[0043] Next, the obtained image information is input via an interface to an image analyzer (for example, image analysis software "Image-Pro PLUS" manufactured by Media Cybernetics, etc.) for analysis, and the projected area of ​​each particle is determined. Note that the projected area is intended to be the projected area of ​​a primary particle. Then, for each particle, the circle-equivalent diameter is calculated from the projected area of ​​the magnetic particle obtained by the above procedure. The circle-equivalent diameter is the diameter of a perfect circle when it is assumed to have the same projected area as the projected area of ​​the magnetic particle at the time of observation. Next, for the 1,000 magnetic particles to be measured, the volume is calculated for each particle using the following formula (1). Formula (1): Volume = (circle-equivalent diameter of magnetic particle) ３ × (π / 6) A particle size distribution curve is obtained based on the volume and circle-equivalent diameter of each magnetic particle obtained above, and the volume-average particle diameter (MV) of the magnetic particles is determined. This volume-average particle diameter corresponds to the average particle diameter described above. From the measurement results, it is confirmed whether or not the magnetic particles have a composition with an average particle diameter of 20 μm or more.

[0044] The content (volume %) of magnetic particles having an average particle diameter of 20 μm or more relative to the total volume of magnetic particles, and the content (mass %) of magnetic particles having an average particle diameter of 20 μm or more relative to the total mass of magnetic particles can be determined by the following procedure. When observing magnetic particles using the SEM, 1,000 randomly selected particles are analyzed for elemental composition using EDS, magnetic particles having a composition similar to that of magnetic particles having an average particle diameter of 20 μm or more are extracted, and the volume of each particle is calculated using the above formula (1). From the values ​​obtained by the above method, the content (volume %) of magnetic particles having an average particle diameter of 20 μm or more relative to the total volume of magnetic particles can be determined. Furthermore, by taking specific gravity into account, the content (mass %) of magnetic particles having an average particle diameter of 20 μm or more relative to the total mass of magnetic particles can be determined.

[0045] The above-mentioned measurements may be carried out after extracting magnetic particle powder from a composition containing magnetic particles and a solvent by any method (such as baking or sedimentation), or may be carried out on a film formed from a composition containing magnetic particles and a solvent. In particular, the above-mentioned measurements are preferably carried out on a film formed from the composition. The film may be a coating film or a cured film. When the charged content of the composition is known, the presence or absence of magnetic particles having an average particle diameter of 20 μm or more in the composition, the content (volume %) of magnetic particles having an average particle diameter of 20 μm or more relative to the total volume of the magnetic particles, and the content (mass %) of magnetic particles having an average particle diameter of 20 μm or more relative to the total mass of the magnetic particles may be determined based on the charged content.

[0046] [Solvent] The composition contains a solvent. The solvent contains at least one specific solvent having a boiling point of 300°C or less and satisfying the relationship of formula (1). That is, the composition contains at least one specific solvent having a boiling point of 300°C or less and satisfying the relationship of formula (1). Formula (1): Vapor pressure of the specific solvent expressed in Torr at 25°C × molecular weight of the specific solvent < 0.53

[0047] The specific solvent is preferably an organic solvent, and is preferably a solvent selected from the group consisting of ether solvents, ester solvents (preferably acetate solvents), ketone solvents, alcohol solvents, and amide solvents; more preferably an ether solvent, further preferably an ether solvent having a structural moiety represented by -AL-O- (AL: ethylene or propylene), still more preferably an ether solvent having a structural moiety represented by (-AL-O-)n (AL: ethylene or propylene, n: repeating unit and an integer of 2 to 8), and most preferably an ether solvent represented by the following formula (A):

[0048] Formula (A): R Ｓ１ -(AL-O)n-R Ｓ２ R Ｓ１ and R Ｓ２ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a hydroxyl group, or a hydroxyl group. AL represents ethylene or propylene. n represents an integer of 2 to 8 (preferably an integer of 3 to 6).

[0049] The upper limit of the boiling point of the specific solvent is 300°C or lower, preferably 280°C or lower, more preferably 260°C or lower, even more preferably 200°C or lower, and particularly preferably 150°C or lower. The lower limit of the boiling point of the specific solvent is not particularly limited, but is preferably 80°C or higher, more preferably 100°C or higher, even more preferably 150°C or higher, and particularly preferably 180°C or higher. For the boiling points of specific solvents, reference can be made to the values ​​listed in the CRC Handbook of Chemistry and Physics, 88th Edition. If the boiling point of the specific solvent is not listed in the handbook, the boiling point at standard atmospheric pressure is determined using a boiling point measuring device (e.g., a Mettler-Toledo "Melting Point System MP80" measuring device).

[0050] The lower limit of the vapor pressure (unit: Torr) of the specific solvent at 25°C is not particularly limited, but is preferably 0.0001 Torr or higher, more preferably 0.0010 Torr or higher. The upper limit of the vapor pressure (unit: Torr) of the specific solvent at 25°C is not particularly limited, but is preferably 0.0040 Torr or lower, more preferably 0.0030 Torr or lower. For the vapor pressure of the specific solvent, reference can be made to the value listed in the Hazardous Substance Data Bank (HSDB). If the vapor pressure of the specific solvent is not listed in the HSDB, it can be measured using known vapor pressure measurement methods such as the gas flow method, static method, isoteniscope method, boiling point method, and DSC method (differential scanning calorimetry).

[0051] The upper limit of the melting point of the specific solvent is preferably −10° C. or lower, more preferably −20° C. or lower, and even more preferably −30° C. or lower, in order to provide a composition with better frozen storage stability. The lower limit of the melting point of the specific solvent is preferably −60° C. or higher, and more preferably −50° C. or higher. The melting point of the specific solvent can be measured using a freezing point measuring device (for example, the "Automatic Freezing Point, Pour Point, and Cloud Point Tester OptiMPP" manufactured by STM Corporation).

[0052] The molecular weight of the specific solvent is not particularly limited, but is preferably 100 to 300, more preferably 150 to 220, and even more preferably 170 to 210.

[0053] The upper limit of the value represented by the left side of the above formula (1) (vapor pressure of the specific solvent at 25°C (unit: Torr) × molecular weight of the specific solvent) is preferably 0.40 or less, and more preferably 0.30 or less, in order to more easily achieve the effects of the present invention. The lower limit is not particularly limited, but is preferably 0.001 or more, and more preferably 0.01 or more.

[0054] Examples of the specific solvent include triethylene glycol monoethyl ether (molecular weight: 178, vapor pressure at 25°C: 0.0022 Torr), hexyl carbitol (molecular weight: 190, vapor pressure at 25°C: 0.0012 Torr), diethyl carbitol (molecular weight: 162, vapor pressure at 25°C: 0.0004 Torr), triethylene glycol (molecular weight: 150, vapor pressure at 25°C: 0.0013 Torr), and triethylene glycol monobutyl ether (molecular weight: 206, vapor pressure at 25°C: 0.0025 Torr). Note that the vapor pressure at 25°C refers to the vapor pressure (unit: Torr) at 25°C.

[0055] The lower limit of the total content of the specific solvents (the total content when multiple solvents are included) is preferably 3% by mass or more, more preferably 4% by mass or more, relative to the total mass of the composition, and the upper limit of the total content of the specific solvents is preferably 35% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, relative to the total mass of the composition.

[0056] The composition may contain a solvent other than the specific solvent. Among other solvents, organic solvents are preferred, and examples thereof include ester solvents (preferably acetate solvents), ketone solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents. The other solvents may be used alone or in combination of two or more.

[0057] The lower limit of the boiling point of the other solvent is preferably 55° C. or higher, more preferably 80° C. or higher, and even more preferably 100° C. or higher. The upper limit of the boiling point of the other solvent is not particularly limited, but is preferably 300° 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.

[0058] Other solvents include, for example, 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), 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), and 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 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 Lithium monobutyl ether acetate (boiling point 192°C), propylene glycol diacetate (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 188°C) ), 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).

[0059] The lower limit of the content of the specific solvent (total content when multiple types are included) is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, particularly preferably 98% by mass or more, and most preferably 99% by mass or more, relative to the total mass of the solvent. The upper limit of the content of the specific solvent is preferably 100% by mass or less, relative to the total mass of the solvent. It is preferable that the solvent in the composition essentially contains only the specific solvent. Here, "substantially" means that the content of solvents other than the specific solvent is 1% by mass or less, relative to the total mass of the solvent.

[0060] [Binder Component] The composition preferably contains a binder component, and more preferably contains a thermosetting compound as the binder component. Examples of thermosetting compounds include epoxy compounds and oxetane compounds. An epoxy compound refers to a compound containing at least one epoxy group. An oxetane compound refers to a compound containing at least one oxetanyl group. In the epoxy compound, 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. A single cyclic group may be fused with only one epoxy group, or two or more epoxy groups may be fused with each other. In the oxetane compound, 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.

[0061] The epoxy compound and 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 oxetane compound is not particularly limited, but is preferably 2000 or less, for example.

[0062] 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); JER1031S and jER630 (all manufactured by Mitsubishi Chemical Corporation); and EPICLON N-695 (manufactured by DIC Corporation).

[0063] Specific examples of bisphenol A epoxy resins and bisphenol F epoxy resins include ZX-1059 (manufactured by Nippon Steel Chemical & Material Co., Ltd.) and 828US (manufactured by Mitsubishi Chemical Corporation). 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 ZX-1658GS (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.).

[0064] 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.

[0065] 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.

[0066] The epoxy compound also includes a compound containing a caprolactone structure represented by the following formula (Z-1).

[0067]

[0068] 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.

[0069]

[0070] 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.

[0071] The epoxy compound also includes compounds represented by the following formula (Z-4) or (Z-5).

[0072]

[0073] 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.

[0074] 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.

[0075] Among the compounds represented by formula (Z-4) or formula (Z-5), pentaerythritol derivatives and / or dipentaerythritol derivatives are more preferred.

[0076] 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.

[0077] 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.

[0078] 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.).

[0079] 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.

[0080] 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.

[0081] 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 mass of the composition. 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.

[0082] [Dispersant] The composition preferably contains a dispersant. The dispersant is a resin that improves the dispersibility of magnetic particles and typically has functional groups that can interact with the magnetic particles (e.g., acid groups, basic groups, coordinating groups, and reactive functional groups). 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 obtained by removing one hydrogen atom 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] When the composition contains resin A, the content of resin A is preferably 1 to 24% by mass, more preferably 0.001 to 20.0% by mass, more preferably 0.01 to 15.0% by mass, even more preferably 0.05 to 10.0% by mass, and particularly preferably 0.05 to 5.0% by mass, relative to the total mass of the composition. The content of resin A is preferably 0.001 to 20.0% by mass, more preferably 0.01 to 15.0% by mass, even more preferably 0.05 to 10.0% by mass, and particularly preferably 0.05 to 5.0% by mass, relative to the total solid content of the composition.

[0090] 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.

[0091] 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):

[0092]

[0093] In formula (4A), R Ｘ１ and R Ｘ２ each independently represents a hydrogen atom or an alkyl group. １ represents 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.

[0094]

[0095] 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.

[0096] * 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.

[0097] 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.

[0098] a in formula (4A) １ and a in formula (4B) ２is 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.

[0099] 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.

[0100] 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):

[0101]

[0102] 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).

[0103]

[0104] 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.

[0105] 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.

[0106] b in formula (5A) １２and b in formula (5B) ２２ each independently represents 0 or 1.

[0107] X in formula (5A) Ａ and X in formula (5B) Ｂ each 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.

[0108] 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).

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.).

[0116] The dispersant may be used alone or in combination of two or more types. 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%, even more preferably 0.05 to 10.0 mass%, and particularly preferably 0.05 to 5.0 mass%, relative to the total mass of the composition. 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%, even 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.

[0117] [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., exhibiting high viscosity when shear stress (shear rate) is low and low viscosity when shear stress (shear rate) is high. 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 mass of the composition. 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 solids content of the composition.

[0118] The thixotropic agent may be an organic thixotropic agent or an inorganic thixotropic agent, with the organic thixotropic agent being preferred.

[0119] <Organic thixotropic agent> When the composition contains an organic thixotropic agent, the content of the organic 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, relative to the total mass of the composition. The content of the organic 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, relative to the total solids content of the composition. The organic thixotropic agents may be used alone, or two or more types may be used.

[0120] 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 group interacts 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 group 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 to 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 preferable 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 curable group (e.g., epoxy group or oxetanyl group) of the binder when producing a magnetic body, and an amide group is preferred because the composition has better stability over time.

[0121] 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.

[0122] 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.

[0123] Examples of organic thixotropic agents include modified urea, urea-modified polyamide, fatty acid amide, polyurethane, polyamide amide, polymeric urea derivative, and salts thereof (such as carboxylates). 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 an 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.

[0124] The molecular weight of the organic thixotropic agent (weight average molecular weight if it 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.

[0125] (Aggregation Control Agent) The organic thixotropic agent also includes an aggregation control agent. The aggregation control agent may be a resin or a non-resin material. The aggregation control agent has the function of binding to relatively dense aggregates such as magnetic particles, and further dispersing components such as binders 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.

[0126] 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.

[0127] 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%, relative to the total mass of the composition. 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%, relative to the total solid content of the composition.

[0128] (Aggregating Dispersant) Examples of organic thixotropic agents include aggregating dispersants. The aggregating dispersant may be a resin or a non-resin material. Aggregating 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 aggregating directly. As a result, aggregation of the magnetic particles is suppressed, and even if aggregates are formed, they are formed with a relatively low density. Furthermore, components such as binders can be dispersed in the composition to form bulky aggregates, which can improve redispersibility.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] One preferred embodiment of the aggregation dispersant is a compound represented by the following formula (II).

[0137]

[0138] In formula (II), R １ represents a monovalent linear aliphatic hydrocarbon group having 10 to 25 carbon atoms, and R２ 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 L １ and L ３ When is —NHCO—, L ２ is -CONH-.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] R ５ and R ６Examples 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.

[0145] 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.

[0146] The compound represented by formula (II) is preferably a compound represented by the following formulas (II-1) to (II-9).

[0147]

[0148] 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).

[0149] 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 even more preferably 0.01 to 6.0 mass%, relative to the total mass of the composition. The content of the aggregating dispersant 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%, relative to the total solid content of the composition.

[0150] <Inorganic thixotropic agents> Examples of inorganic thixotropic agents include bentonite, silica, calcium carbonate, and smectite.

[0151] [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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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).

[0156] 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.

[0157] 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.

[0158] Specific examples of carbodiimide curing agents include "V-03" and "V-07" manufactured by Nisshinbo Chemical Inc.

[0159] Commercially available amine adduct curing agents include, for example, Amicure PN-23 and PN-50 (both manufactured by Ajinomoto Fine-Techno Co., Ltd.).

[0160] When the composition contains a curing agent, the ratio of the binder content to the curing agent content is preferably such that the equivalent ratio ("total number of epoxy groups and oxetanyl groups") / "number of reactive groups") between the epoxy groups and oxetanyl groups contained in the binder and the reactive groups in the curing agent (active hydrogen groups such as hydroxyl groups in the curing agent) is 30 / 70 to 70 / 30, more preferably 40 / 60 to 60 / 40, and even more preferably 45 / 55 to 55 / 45. The curing agent content is preferably 0.001 to 3.5% by mass, more preferably 0.01 to 3.5% by mass, based on the total mass of the composition. The curing agent content is preferably 0.001 to 3.5% by mass, more preferably 0.01 to 3.5% by mass, based on the total solids content of the composition.

[0161] [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 a triarylphosphine include the compounds described in paragraph

[0024] of JP 2014-5382 A. 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 0.01 to 1.0 mass%, relative to the total mass of the composition. 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 solids content of the composition.

[0162] [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, a surfactant, an adhesion aid (e.g., 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.

[0163] [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, in order to achieve 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).

[0164] [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, etc.). 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.

[0165] [Uses] The composition can be suitably used as a hole-filling composition for holes (such as via holes and through holes, which may be through holes or blind holes) formed in a substrate. A specific example of a hole-filling procedure includes the following steps 1 to 3: Step 1: Applying the composition to the surface of a substrate having holes such as via holes or through holes by a known coating method such as slit coating, inkjet coating, spin coating, casting coating, roll coating, or screen printing to fill the holes; Step 2: Heating the composition on the substrate that has undergone step 1 at, for example, about 120 to 180°C for 30 to 90 minutes to cure the thermosetting component in the composition; and Step 3: Removing unnecessary portions of the magnetic material obtained in step 2 that protrude from the substrate surface by physical polishing to form a flat surface. Substrates containing the magnetic material are suitably used, for example, as electronic components such as antennas and inductors that are equipped in electronic communication devices and the like.

[0166] The filling step of step 1 may be carried out in either a normal pressure environment or a reduced pressure environment. Among these, the filling step of step 1 is preferably a step of applying the magnetic composition by a screen printing method in a reduced pressure environment (preferably a vacuum) to fill the holes with the magnetic composition.

[0167] The heat treatment in step 2 may be carried out multiple times by changing the heating temperature and heating time. The heating temperature in the heat treatment in step 2 is preferably 80 to 240°C, more preferably 100 to 220°C, and even more preferably 100 to 200°C. The heating time is preferably 30 to 240 minutes, more preferably 30 to 180 minutes. The heat treatment can be carried out continuously or batchwise using a heating means such as a hot plate, a convection oven (hot air circulation dryer), or a high-frequency heater.

[0168] Another use of the composition is as a film-like magnetic material (hereinafter also referred to as a "magnetic particle-containing film"). An example of a method for producing a magnetic particle-containing film is a method including a composition layer forming step and a curing step.

[0169] In the composition layer forming step, a composition is applied to the surface of a substrate to form a layer of the composition (composition layer). The substrate may be, for example, a wiring board.

[0170] As a method for applying the composition to the surface of the substrate, various coating methods such as slit coating, inkjet coating, spin coating, casting coating, roll coating, and screen printing can be used. The film thickness of the composition layer is preferably 1 to 10,000 μm, more preferably 10 to 1,000 μm, and even more preferably 15 to 800 μm. The composition layer applied to the surface of the substrate may be heated (prebaked). Prebaking is performed, for example, on a hot plate or in an oven at a temperature of 50 to 140° C. for 10 to 1,800 seconds.

[0171] The curing step may include a heat treatment for heating the composition layer. The heat treatment may be carried out continuously or batchwise using a heating means such as a hot plate, a convection oven (hot air circulation dryer), or a high-frequency heater. The heating temperature in the heat treatment is preferably 120 to 260°C, more preferably 150 to 240°C. The heating time is not particularly limited, but is preferably 10 to 1800 seconds. The pre-baking in the composition layer formation step may also serve as the heat treatment in the curing step. The substrate containing the magnetic material is suitable for use as electronic components such as antennas and inductors installed in electronic communication devices, etc.

[0172] [Magnetic Material] The magnetic material of the present invention is a product formed by subjecting the above-mentioned composition to a heat treatment, and is typically a resin containing magnetic particles formed by subjecting the above-mentioned composition containing a binder component to a curing treatment by heating. The shape of the magnetic material is not particularly limited, and for example, as described above, it may be a shape that fits the shape of a hole provided in a substrate, or it may be in the form of a film.

[0173] [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.

[0174] 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."

[0175] [Various Components Contained in the Composition] The various components used in preparing the composition are listed below.

[0176] [Magnetic Particles] The various components shown in the "Magnetic Particles" column in Table 2 are shown below. P-1: Product name "AW2-08 PF-3F" (manufactured by Epson Atmix Corporation, spherical magnetic particles, D90: 6.3 μm) P-2: Product name "ATFINENC1 PF3FA" (manufactured by Epson Atmix Corporation, spherical magnetic particles, D90: 4.7 μm) P-3: Product name "EA-SMP-10 PF-5F" (manufactured by Epson Atmix Corporation, spherical magnetic particles, D90: 8.9 μm) P-4: Mn ferrite (manufactured by Powder Tech Corporation, spherical magnetic particles, D90: 9.5 μm) P-5: Mn ferrite (manufactured by Powder Tech Corporation, spherical magnetic particles, D90: 2.1 μm) P-6: NiZn ferrite (manufactured by Powder Tech Corporation, spherical magnetic particles, D90: 9.9 μm) P-7: MnZn ferrite (manufactured by Powder Tech Co., Ltd., spherical magnetic particles, D90: 7.8 μm) P-8: Product name "KUAMETNC1 53C03A" (manufactured by Epson Atmix Corporation, spherical magnetic particles, D90: 53.7 μm) P-9: Ni-Zn-Co ferrite (manufactured by Japan Metals and Chemical Industries Co., Ltd., spherical magnetic particles, D90: 60.3 μm) P-10: MnZn ferrite (manufactured by Powder Tech Co., Ltd., spherical magnetic particles, D90: 59.1 μm) P-11: Mn ferrite (manufactured by Powder Tech Co., Ltd., spherical magnetic particles, D90: 59.4 μm)

[0177] [Thioctropic Agents] The various components shown in the "Thioctropic Agent" column in Table 2 are listed below. T-1: Product name "FLOWNON RCM-100" (manufactured by Kyoeisha Chemical Co., Ltd.) T-2: Product name "Tallen VA705B" (manufactured by Kyoeisha Chemical Co., Ltd.) T-3: Product name "Disperbyk 111" (manufactured by BYK)

[0178] [Dispersant] The various components shown in the "Dispersant" column in Table 2 are shown below. D-1: Product name "Hinoact T-6000" (manufactured by Kawaken Fine Chemicals Co., Ltd.) D-2: The following compound (weight average molecular weight 10,000). The numbers attached to each repeating unit in the main chain represent the mass ratio, and the numbers attached to the side chains represent the number of repeats.

[0179]

[0180] ・D-3: Product name “SC-1015F” (manufactured by NOF Corporation)

[0181] [Curing components] The various components shown in the "Curing components" column in Table 2 are shown below. C-1: Product name "EPICLON N-695" (manufactured by DIC Corporation) C-2: Product name "Denacol EX-614" (manufactured by Nagase ChemteX Corporation) C-3: Product name "Denacol EX-512" (manufactured by Nagase ChemteX Corporation) C-4: Product name "ZX-1059" (manufactured by Nippon Steel Chemical & Material Co., Ltd.) C-5: Product name "ZX-1658GS" (manufactured by Nippon Steel Chemical & Material Co., Ltd.) C-6: Product name "jER630" (manufactured by Mitsubishi Chemical Corporation)

[0182] [Additives] The various components shown in the "Additives" column in Table 2 are listed below. A-1: ​​Product name "Hishicolin PX-4MP" (phosphate-based epoxy curing accelerator, manufactured by Nippon Chemical Industry Co., Ltd.) A-2: Product name "2MZA-PW" (2-ethyl-4-methylimidazole (curing accelerator), manufactured by Shikoku Kasei Holdings Co., Ltd.) A-3: Product name "SO-C2" (silica particles, manufactured by Admatechs Co., Ltd.) A-4: Product name "KBM-573" (N-phenyl-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0183] [Solvent] Table 1 shows the various components shown in the "Solvent" column in Table 2. In the table, 1,6-HDDA is 1,6-hexanediol diacetate, and NMP is N-methylpyrrolidone. In Table 1, the "vapor pressure" indicates the vapor pressure (unit: Torr) at 25°C.

[0184]

[0185] [Preparation of Compositions of Examples and Comparative Examples] The components other than the solvent shown in Table 2 were mixed to give the composition (parts by mass) shown in Table 2, and the mixture was placed in a sealed container made of PTFE (polytetrafluoroethylene). Subsequently, a solvent was added to give the composition (parts by mass) shown in Table 2, and the container was then sealed. The mixture was dispersed at 50 G for 1 hour using a RAM (low frequency resonant acoustic mixer) manufactured by Resodyn Corporation, to prepare the compositions of each of the Examples and Comparative Examples.

[0186]

[0187]

[0188]

[0189] [Evaluation] [Stability under reduced pressure] 100 g of a given composition was placed in a vacuum chamber, and the pressure inside the chamber was reduced to 0.1 Torr using a rotary pump. The pressure inside the chamber was then reduced to 2 Torr, and this pressure was maintained at 25°C for 72 hours. The composition was then removed from the chamber, which had been returned to normal pressure, and the weight of the composition (hereinafter also referred to as the "weight after degassing") was measured. The composition was then heated at 100°C for 5 hours in an oven, and the weight of the composition after heating (hereinafter also referred to as the "weight after drying") was measured. The volatilization rate was then calculated using the following formula (2). In formula (2), the initial weight refers to the initial weight of the composition before the reduced pressure treatment. In the volatilization rate, (initial weight - weight after degassing) represents the amount of solvent volatilized under reduced pressure, and (initial weight - weight after drying) represents the amount of solvent volatilized after the 5-hour curing process at 100°C. The volatilization rate represents the ratio of the amount of solvent volatilized under reduced pressure conditions to the total mass of solvent volatilized when the process up to the curing step is carried out, and the smaller this value, the less likely the solvent is to volatilize under reduced pressure conditions. Therefore, the smaller the volatilization rate, the less likely the properties of the composition are to change under reduced pressure conditions, and the better the reduced pressure applicability. Formula (2): Volatilization rate (mass%) = {(initial weight - weight after degassing) / (initial weight - weight after drying)} x 100

[0190] The volatility rate of the composition of Comparative Example 1 was normalized to 1, and the relative values ​​of the compositions of the Examples and Comparative Examples were determined. The obtained values ​​were then classified and evaluated based on the following evaluation criteria. A rating of "3" or higher is preferred.

[0191] <Evaluation criteria> "5": Less than 0.8 "4": 0.8 or more and less than 0.9 "3": 0.9 or more and less than 1.0 "2": 1.0 or more and less than 1.1 "1": 1.1 or more

[0192] [Increase in foreign matter before and after frozen storage] 100 g of a given composition was stored at -20°C for 6 months. After storage under the above conditions, it was left to thaw at 25°C for 12 hours. Next, the thawed composition was applied to a thickness of 100 μm using an applicator, and the surface condition was visually confirmed. The same test was also carried out on the composition before freezing, and by comparing the surface condition, the increase in foreign matter before and after frozen storage was observed, and evaluation was carried out according to the following evaluation criteria. <Evaluation criteria> "2": No increase in foreign matter was observed before and after freezing. "1": An increase in foreign matter was observed before and after freezing.

[0193] [Magnetic Properties] <Preparation of Measurement Sample Substrate> A substrate was prepared by forming a coating film of CT4000 (FUJIFILM Electronic Materials Co., Ltd.) on a 100 μm thick Si wafer. Each composition of the Examples and Comparative Examples was applied to the coating film on the substrate using an applicator with a gap of 100 μm, followed by a heat-drying treatment at 100° C. for 120 seconds and then a heat treatment at 230° C. for 15 minutes to completely cure the film. After curing, the substrate with the film was cut into 1 cm × 2.8 cm pieces to obtain a measurement sample substrate.

[0194] <Preparation of Reference Substrate for Measurement> Using the magnetic particles contained in each composition of the Examples and Comparative Examples (however, when a composition contains a combination of multiple magnetic particles, the mixture ratio is the same), a reference composition having the following composition was prepared: (Reference Composition) Magnetic particles: 85.8% by mass Dispersant D-1 described above: 5.2% by mass Solvent L-1 described above: 9.0% by mass

[0195] Taking Composition 1 as an example, which uses 43 parts by mass each of Particles P-1 and P-8 as magnetic particles, a reference composition for Composition 1 is prepared as follows: Particles P-1: 42.9% by mass Particles P-8: 42.9% by mass Dispersant D-1 described above: 5.2% by mass Solvent L-1 described above: 9.0% by mass

[0196] Next, a film-coated substrate was prepared using the above reference composition in the same procedure as in <Preparation of Sample Substrate for Measurement>, and this was used as a reference substrate for measurement.

[0197] (Evaluation of Magnetic Properties) The magnetic properties of the measurement sample substrate and the measurement reference substrate were measured using a magnetic material property measurement system "PER-01" (manufactured by Keycom Corporation), and μ'A, which is the magnetic permeability μ' of the measurement sample substrate, and μ'B, which is the magnetic permeability μ' of the measurement reference substrate, were obtained. The magnetic permeability ratio (Δμ') of the measurement sample substrate to the measurement reference substrate was derived using the following mathematical formula (3). The larger the magnetic permeability ratio (Δμ'), the less solvent remains in the cured film in the measurement sample substrate and the relatively higher the magnetic particle content in the cured film, making it possible to maintain the desired magnetic properties. A rating of "2" or higher is preferred. Mathematical formula (3): Δμ' = μ'A / μ'B (Evaluation criteria) "3": Δμ' is greater than 0.9 "2": Δμ' is greater than 0.75 and 0.9 or less "1": Δμ' is 0.75 or less

[0198]

[0199] The results in Table 3 clearly show that the compositions of the examples have excellent reduced-pressure applicability and contain little residual solvent in the product obtained after heat treatment. The results of the examples (see particularly the results of Examples 5, 9, and 10) confirmed that when the value represented by the left side of the above formula (1) for the specific solvent contained in the composition (the vapor pressure of the specific solvent at 25°C (unit: Torr) x the molecular weight of the specific solvent) is 0.45 or less, the reduced-pressure applicability (application stability under reduced pressure) is superior. The results of the examples (see particularly the result of Example 17) confirmed that when the composition essentially contains only the specific solvent as the solvent, the reduced-pressure applicability is superior. The results of the examples (see particularly the results of Examples 4, 8, 10, and 17) confirmed that when the melting point of the specific solvent is -10°C or less, the generation of foreign matter is suppressed when the composition is used after frozen storage. The results of the examples (see particularly the results of Examples 13 and 14) confirmed that when the content of magnetic particles in the composition is 90% by mass or more relative to the total solids content of the composition, the magnetic performance is superior.

[0200] In Comparative Examples 1 to 3, the solvent contained in the composition did not satisfy formula (1), and the desired reduced-pressure coatability was not obtained. On the other hand, in Comparative Example 4, the composition contained a diluent monomer instead of a solvent in an amount sufficient to achieve the desired coatability, but the magnetic particle content in the product obtained after heat treatment was expectedly low, and therefore the desired magnetic properties were not obtained.

Claims

1. A composition comprising magnetic particles and a solvent, wherein the solvent has a boiling point of 300°C or less and contains at least one specific solvent that satisfies the relationship of formula (1): (vapor pressure of the specific solvent expressed in Torr at 25°C × molecular weight of the specific solvent) < 0.53 2. The composition according to claim 1, wherein the melting point of the specific solvent is -10°C or lower.

3. The composition according to claim 1 or 2, wherein, when the composition contains one type of magnetic particles, the average particle size of the magnetic particles is 20 μm or more, and when the composition contains two or more types of magnetic particles with different compositions, the two or more types of magnetic particles include at least one type of magnetic particle with an average particle size of 20 μm or more.

4. The composition according to claim 1 or 2, wherein the total content of the specific solvents is 3 mass% or more relative to the total mass of the composition.

5. A magnetic body obtained by curing the composition according to claim 1 or 2.

6. A substrate with a magnetic material, comprising: a substrate having a hole formed therein; and the magnetic material according to claim 5, disposed in said hole.

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

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